How do you identify a double-crested cormorant?

What is a double-crested cormorant?

The double-crested cormorant (Phalacrocorax auritus) is a large waterbird found across North America. As their name suggests, they have two distinctive crests on their head, particularly in breeding season. Double-crested cormorants are adept swimmers and divers, using their feet to propel themselves underwater as they pursue fish. They are a common sight along coastlines, rivers, and lakes across much of the continent.

Some quick facts about double-crested cormorants:

• Scientific name: Phalacrocorax auritus
• Length: 30-36 inches
• Wingspan: 4.5 feet
• Weight: 2.5-5.5 pounds
• Lifespan: up to 17 years
• Diet: Predominantly fish
• Range: Throughout much of North America

Now let’s discuss how to positively identify them.

Distinctive physical features

Double-crested cormorants have a unique appearance with several readily apparent features that aid identification:

• Two crests – In breeding season, the black feathers on the top and sides of their heads form two distinctive thin, upswept crests, hence their name.
• Orange facial skin – Their face has bare orange skin, especially around the eyes and mouth.
• Long neck – They have an elongated neck and body for diving.
• Hooked bill – Their bill is thick and hooked at the tip.
• Webbed feet – Their feet are fully webbed for swimming.
• Dark coloration – Adults are all black with a brownish hue.
• Turquoise eyes – They have striking turquoise eyes.

The combination of crests, orange face, and long neck gives double-crested cormorants a very distinctive profile both on land and in the water. Their solid black plumage and bright blue eyes are also quite striking.

Differences from similar birds

Some other aquatic birds share certain traits with double-crested cormorants, but all can be differentiated by examining certain features:

Anhinga

• Long neck and beak like cormorants
• Differences:
  • Male anhingas have a black head and silvery white body
  • No orange facial skin
  • Don’t hold wings out to dry like cormorants

American white pelican

• Large waterbird with long beak
• Differences:
  • White plumage
  • Large throat pouch
  • Orange bill

Cormorant vs. loon

• Both are dark waterbirds that dive
• Differences:
  • Loons have a thicker, straight bill
  • Cormorants have a longer, hooked neck
  • Loons have a checkerboard back pattern

Cormorant vs. merganser

• Both have crested heads
• Differences:
  • Mergansers have a shaggy crest vs. sleek on cormorants
  • Mergansers have white bodies
  • Mergansers have thinner, serrated bills

So in summary, the double-crested cormorant can be positively identified by its distinctive thin double head crests, black plumage, orange facial skin, bright turquoise eyes, elongated neck, thick hooked bill, and fully webbed feet.

Behavior and habitat

Double-crested cormorants are most commonly found in areas with ample food sources and suitable habitat for nesting and roosting. Some key behavioral notes and habitat preferences:

• Excellent swimmers and divers, can dive up to 30 feet underwater.
• Often seen standing with wings spread out to dry.
• Nest in colonies on islands, cliffs, trees, or artificial structures.
• Roost communally on poles, wires, rocks, and other structures.
• Forage on small fish in estuaries, rivers, lakes, and along coastlines.

Their habitat ranges from coastal areas to inland lakes and rivers. But they are always found near fish-filled waters where they can successfully hunt and dive for food.

Range and distribution across North America

Double-crested cormorants live along the Pacific, Atlantic, and Gulf coasts, as well as inland lakes, rivers, and wetlands across much of North America.

West Coast

Found along the Pacific coast from Alaska to Mexico. Common in estuaries, bays, harbors, and other coastal wetlands.

East Coast

Ranges along the Atlantic coast from Maine to Florida. Frequent in saltwater bays, lagoons, marshes, and river mouths.

Gulf Coast and Southern States

Occupies the Gulf coast, Florida wetlands, lakes, and major rivers of the southern U.S.

Northern States

Summers across the Great Lakes region and as far north as southern Canada. Many migrate further south for winter.

Interior Region

Present year-round on inland lakes, rivers, and marshes. Concentrated around major waterways and wetlands.

Across their continental range, double-crested cormorants can be found anywhere with adequate food supplies, nesting sites, and habitats with shallow, fishable water. They thrive around varied aquatic habitats from coast to coast.

Conclusion

In summary, the double-crested cormorant is identified by its distinctive black plumage, long hook-tipped bill, bright blue eyes, two thin head crests, orange facial skin, elongated neck, webbed feet, and its habit of standing with wings spread to dry. A successful fish-eater, it lives across North America in coastal and inland waters that support populations of small fish for their diet. With their excellent diving and swimming skills, these adaptable waterbirds flourish around both saltwater and freshwater habitats.

Other key identification traits

• Size – 30-36 inches long, 4.5 foot wingspan
• Male and female identical in appearance
• Immature birds lack crests, have lighter plumage
• No seasonal plumage differences

While identification is straightforward for adults, juvenile double-crested cormorants can be more challenging to recognize before they attain full adult plumage. Immature birds lack the signature double crests and have a lighter brownish color instead of solid black. But they gradually take on adult characteristics over their first year.

Some cormorant species like the great cormorant found in Europe appear very similar. But within North America, the double-crested cormorant is distinctive and unlikely to be confused with other diving waterbirds when its identifying features are recognized.

Threats and conservation

Double-crested cormorant populations declined during the mid-20th century due to DDT pesticide contamination and human persecution. But with protection under the Migratory Bird Treaty Act and reduction in toxic pollution, their numbers increased significantly by the 1980s.

Today they number over 1 million in North America and their adaptable nature allows them to thrive in a wide range of habitats. But some concerns remain:

• Climate change impacting food supplies and nesting sites
• Population conflicts in some areas due to impacts on commercial fish stocks
• Legal culling/control programs in place in some regions to reduce numbers

Sustainable management practices and habitat conservation will be important going forward to ensure the continued success of double-crested cormorant populations while addressing specific local conflicts.

How you can help

Some tips for supporting double-crested cormorants and other waterbird conservation:

• Follow regulations on bird harassment to avoid disturbing nesting colonies
• Dispose of fishing line responsibly to avoid entanglement
• Support wetland restoration and protection programs in your region
• Report sightings and volunteer for bird surveys
• Limit plastic pollution that can impact aquatic food sources

With some thoughtful stewardship, these remarkable diving birds will continue thriving across North America’s waterways for generations to come.